Refrigerated vehicle

ABSTRACT

A refrigerated vehicle has at least two successive underfloor tanks for liquefied gases at low temperature wherein each tank has a filling aperture, an overflow aperture, and a discharge aperture. The overflow aperture of one tank is connected by a pipe to the filling aperture of the next successive adjacent tank and the aperture of all tanks are interconnected by way of a common pipe from which a discharge pipe is branched off, and each tank being situated higher than its next successive adjacent tank.

United States Patent [191 Kleffmann eta].

[451 Apr. 16, 1974 REFRIGERATED VEHICLE Inventors: Jurgen Kleffmann; Wilfried Duesberg, both of Frankfurt, Main, Germany Assignee: Messer Griesheim GMBH,

Frankfurt] Main, Germany Filed: 0a. 2, 1972 Appl. No.: 293,830-

Foreign Application Priority Data Oct. 1,1971 Germany 7137319 US. Cl. 62/55, 62/514 Int. Cl F25b 19/00 Field of Search 62/55, 514

References Cited UNITED STATES PATENTS 8/1949 Deutsch 52/514 8/1949 Johnson ..62/514 11/1966 Kane ..62/514 Primary Examiner-Meyer Perlin Attorney, Agent, or Firm--Conno1ly and Hutz 7] ABSTRACT A refrigerated vehicle has at least two successive underfloor tanks for liquefied gases at low temperature wherein each tank has a filling aperture, an overflow aperture, and a discharge aperture. The overflow aperture of one tank is connected by a pipe to the filling aperture of the next successive adjacent tank and the aperture of all tanks are interconnected by way of a common pipe from which a discharge pipe is branched off, and each tank being situated higher than its next successive adjacent tank.

3 Claims, 1 Drawing Figure PATENTEDAPR 16 1914 A I38O3Q859 1 REFRIGERATEDVEHICLE BACKGROUND on THE INVENTION This invention relates'to arefrigeratedvehicle having at least two underfloortanks for a liquefied'gasat low temperature. I a 1 Refrigerated vehicles having a single underfloor tank are known; addition, tank arrangements have been disclosed which c'ompriseat least two tanks and in whicheach tank has a filling aperture, an overflow apthe first tank being connected by way of a pipe to the filling aperture of the'second tank and'the outlet apertures of the first and second tanks being connected by way of a pipe, from which a dischargepipe is branched off.

Through thisknown arrangement, uniform filling is made possible in the case of stationary tanks. In addition, the direct connection of the outlet apertures enables the tanks to be connectedin parallel and to be emptied uniformly.

SUMMARY OF THE INVENTION The object of the invention is to provide a refrigerated vehicle having atlleast, two underfloor tanks which can be uniformly filled and emptied? even when th height at which they are situated varies.

To this end, thepresent invention consists in a refrigerated vehicle having at leasttwo underfloor tanks for liquefied gases at low temperature, whereineach tank has afilling aperture, anoverflow aperture, and a dis charge-aperture, characterizedin that the overflow aperture, and an outlet aperture, the overflow aperture of.

by way of example a preferred embodiment of a refrigerated vehicle in accordance therewith shown in perspective.

DETAILED DESCRIPTION The refrigerated vehicle has two successive underfloor tanks 11 and 12 which are disposed one behind the other and in which the liquefied gas at low temperature,for example nitrogen, which is required for the refrigeration of a space 13, is stored. The two tanks 11 and 12 are connected through a discharge pipe 14 to a spray pipe 15, which is disposed under the roof of the space 13. Parallel to thespray pipe 15 there is a temperature sensor 16, which in conjunction with a diagrammatically illustrated control device 17 controls the amount of liquid nitrogen supplied to the refrigerated space 13. A filling connection 18 and an outlet valve 19 are also provided in the control device 17.

Thefirst tank 11 and the second tank 12 have filling apertures 20, 21, overflow apertures 22, 23 and discharge apertures 24, 25, respectively.

The overflow aperture 20 of the first tank 11 is connected by a pipe 26 to the filling aperture 21 of the second tank 12'. In addition, the discharge apertures 24 and 25 of the first and second tanksll, 12 are connected by a pipe 27 from which the discharge pipe 14 branches off, and the first tank 11 is disposed in a higher position in the vehicle than the second tank 12,

erture of the first tankis connected by way of apipeto the filling aperture ofthe secondtank, the overflow aperture of the second tank is connected by way of a pipe to the filling apertureof a third'tank',if present, and so on, and the discharge aperturesof both or alltanksare interconnected by way of a pipe, from which a dischargepipe is branchedoff, and that the first tank is situated atiahigher levelin the vehicle than the second tank and'the second-tank is situated at ahigher level in the vehicle than the third tank, if present, andso on,

By virtue of this arrangement uniform filling and also uniform emptying are made possible. During filling, the first tank is first filled, while however, at the same time a certain amount of the liquefied gas at low temperature flows into the second tank throughthe pipe at the withdrawal apertures, andpre-cools this tank. As soon as the first tank has been filled, the gas, for example nitrogen, flows through the pipe which is disposed between the overflow aperture of the first tank and the filling aperture of the second tank and into the second tank. Due to the differentheights at which the tanks are disposed the pre-cooling of the second tanks is on the one hand improved, whereby the amount of gas produced by vaporization in the second tank during the filling operation is reducedto a minimum, so that this gas does not affect the operation of filling the second tank, while on the other handthe arrangement of the tanks at different heights ensures efficient filling and emptying even when there is a change in the height in the difference inheight amounting to the distance A (for example 5-10 mm). t I

This arrangement permits uniform filling and also uniform emptying even when the heights at which the tanks are situated varies in the direction of the arrows B. This variation inheight may, for example, be caused byth e loading and unloading of the refrigerator vehicle. In addition, the. height at which the tanks are situatedvaries when the refrigerator vehicle is in the form I of a semitrailer unit and the semitrailer is disconnected which the containers are disposed. A variation in this height occurs, inter alia, during the loading and unloading of the refrigerated vehicle.

from or connected to the tractor; During filling, liquefied nitrogen is passed through the filling connection 18 and the pipe 29 to the filling aperture 20 of the first tank. During the operation of filling the first tank, nitrogen flows through the connection 24, pipe 27 and connection 25 into the second tank 12, and pre-cools the latter. After the first tank 11 has been filled, the nitrogen flows through the overflow aperture 22 and the pipe 26 into the second tank 12, which has already been one-third filled because of the difference in height at which the tanks are situated, and the said second tank is then completely filled. The overflow aperture 22 is preferably disposed in the tank 11 in such a manner that the nitrogenoverflows into the second tank only when the first tank has been almost completely filled.

During emptying, the nitrogen flows uniformly from the two tanks through the pipes 27 and 14 to the spray pipe 15. It is particularly advantageous for the pipe 26 to have a larger diameter than the pipe 27. These diameters could for example be: inch for pipe 26 and inch for pipe 27.

In the embodiment illustrated two tanks are disposed under the floor, but it is of course possible and within the scope of the invention to provide more than two tanks in which case, for example when three tanks are provided, the overflow aperture of the second tank is connected to the filling aperture of the third tank and allthree withdrawal apertures are connected by a pipe,

from which a discharge pipe is branched off, and the third tank is disposed at a lower level than the second tank.

What is claimed is:

l. A refrigerated vehicle having at least two successive underfloor tanks for liquefied gases at low temperature, wherein each tank has a filling aperture, and overflow aperture, and a discharge aperture, characterized in that the tanks are horizontally disposed in the vehicle whereby the vertical dimension of each tank is less than its horizontal dimension, the overflow aperture of one tank being connected by way of a filling pipe to the filling aperture of the next successive tank fled gas is nitrogen. 

1. A refrigerated vehicle having at least two successive underfloor tanks for liquefied gases at low temperature, wherein each tank has a filling aperture, and overflow aperture, and a discharge aperture, characterized in tHat the tanks are horizontally disposed in the vehicle whereby the vertical dimension of each tank is less than its horizontal dimension, the overflow aperture of one tank being connected by way of a filling pipe to the filling aperture of the next successive tank for series filling, the discharge apertures of all tanks being interconnected by way of a common pipe, from which a discharge pipe is branched off for parallel discharge, each tank being situated at a higher level in the vehicle than its next successive tank, and the filling pipe being of greater flow capacity than the discharge pipe.
 2. A vehicle as set forth in claim 1 wherein there are at least three successive underfloor tanks.
 3. A vehicle as set forth in claim 1 wherein the liquefied gas is nitrogen. 